| 摘要 |
PROBLEM TO BE SOLVED: To provide a rotary foil trap in which transmissivity of EUV light is not lowered, temperature rise of a foil is suppressed and the foil has a sufficient lifetime, even in high input operation of an EUV light source.SOLUTION: One end part of each foil 4a is inserted in each of a plurality of grooves 4d provided on a side face of a center pillar 4c, and the center pillar 4c is fixed to each foil 4a by brazing. Gold solder is preferable as brazing filler metal used for the brazing. The center pillar 4c is formed into a truncated cone shape, a temperature gradient in the foil is thereby alleviated compared with a case where the center pillar is formed into a cylinder shape, and groove processing for mounting foil is facilitated. In addition, deformation due to the temperature gradient of the foil can be reduced by setting a thickness of the foil 4a in a range of 0.2 mm-0.5 mm. Furthermore, the temperature of each foil can be maintained at a temperature which is not less than a melting point of a raw material of plasma, less than an evaporation temperature thereof, and a recrystallization temperature of a material forming the foil or less, by providing a pipe conduit in the inside of the center pillar 4a for a fluid to flow. |
